2-Scale Hierarchical Multiscale Modeling of Piezoresistive Response in Polymer Nanocomposite Bonded Explosives

The current work aims to explore the effective piezoresistive response of polymer bonded explosive (PBX) materials where the polymer medium is reinforced with carbon nanotubes (CNTs). The effective piezoresistive response of these nanocomposite bound polymer explosives (NCBX) is evaluated using micromechanics based 2-scale hierarchical model connecting the CNT-polymer nanocomposite scale (nanoscale) to the explosive grain structure scale (microscale). The binding nanocomposite medium is modeled as electromechanical cohesive zones between adjacent explosive grains which are representative of effective electromechanical response of CNT-polymer nanocomposites. The hierarchical framework developed here is used to explore key features of the NCBX microstructure, e.g. ratio of grain to nanocomposite stiffness, ratio of grain to nanocomposite conductivities etc., and related to the NCBX effective piezoresistive response. The results obtained from the current work show dependence of effective NCBX piezoresistive properties on each of these microstructural features with and without interfacial damage between the explosive grains.